Polynitroesters of ethylenically unsaturated carboxylic acids



3,254,343 Patented August 2, 1966 POLYNITROETERS F ETHYLENICALLY I V UNSATUR-ATED, CARBOXYLIC-ACIDS Gustave 1!. Linden, Short Hills. NJ. assignor to Aerojetgleneral Corporation; 'Azus'a, Calif a corporation of I0 No Drawing. Filed-1311129, 1962, Ser. No. 186,273 4 Clairnstv (Cl. 260-486) v This invention relates to novel high energy polynitro esters of. ethylenically unsaturated carboxylic acids, and to their method of preparation. I

It is anobject of'this invention to prepare new energetic polynitro conipounds. Another object of this invention' is to prepare new ethylenically unsaturated polynitro com p'oun'ds which'c'an'be readily polymerized with themselves on with other ethyl'enically unsaturated comonomers to.

form polymeric binders suitable .for use in high energy fuel compositions. These and other objects of my inven tion will appear hereinafter. m

The. new polynit'ro esters of this invention have the following general formula:

wherein R is selected from the, group consisting. of hydrogen and lower atkyt; i.e. methyl, pentyl, decyl, etc.,'

R is a lower alkyl or lower nitroalkyl group containing from 1 to about 10 carbon atoms, such as methyl, ethyl,

decyl, tertiary butyl, Z-nitropropyl 'or 2,4fdinitrop'entyl;

' X, and Z are lower alkylene radicals such as ethylene,

pentamethylene, and decamethylene; and m iszero 'or l. The groups R, R', .X, Y andZ may be branched or straight chain. These new compounds are prepared in Not wherein-R, R, X, Y, Z and m are as defined above.

This reaction is preferably, although not necessarily, conducted in the presence of an acidc'atalyst such as trifiuoroacetic anhydride. or polyphosphoric acid. Thereaction temperature is not critical. Normally the reaction is run at a temperature between about C.

and about 100 C. The preferred temperature is from about 20 C.'to about 50 C. The proportions of the acid and polynitroalcohol employed in'the above reaction-may percent H, 4.l4: percent N. 19.17.

are normally solids and may be isolated in conventional 1 manner by tilt-ration, crystallization. and/or evaporation.

Since the acid reactants of this invention'contain ethylenic unsaturationitis preferred that the esterification be carriedout in the presence of an effective amount; i.e., from about 05% to about 3% by weight of reactants; of a polymerization inhibitor such as hydroquinone.

To more clearly illustrate my invention the followingexamples are presented. It is to be understood however that these examples are intended merely as illustrative embodiments of the invention and should not be construed as limitative ofthe scope of said invention. in any way. In the examples percentages are by weight unless otherwise indicated.

' acrylale At room temperature 0.022 mole of 3,5,5 trinitro- 3-azal-hexanol (this compoundmay be prepared by the method 'disclosed in US. Patent No. 3.000.957, issued September 19,1961) was added to a mixture of 0.026 mole of trifiuoroacetic anhydride and 0.039 mole of re'distilled .acrylic acid, containing a small amount'of hydroquinone.

The reaction was mildly exothermic. The mixture became homogeneous on heating to 35 C. It was held at 35 to 40 C. for minutes and left overnight in a cold container at 5 C. On dilution with water an'oil was This was taken up in methylene chloride,

produced. washed twice with water, and dried. The product was recrystallized twice from'methanol to give'a 62 percent yieldof 3.5,5-trinitro-3-aza-l-hcxyl acrylatc. in the' form of colorless plates having a melting point of 56-57 C. v

Anul vsis.Calc'd for C H N O percent 'C, 3Z.88; Found: percent C, 33.10; percent H, 4.19; percent N, 19.19.

. \Vhe'n Example I is repeated using 4.7,7-trinitro-4-azaoctanol, or 3,5,5,7,7,9,9-heptanitro-3-aza-l-decanol in place 0f 3;5,5-trinitro-3'aza-l-hexanol; and methacrylic acid in place of acrylic acid, 4,7,7-trinitro-4-aza-octyl methacrylate and 3,5.5.7,7,9,9 heptanitro-3-'aza-l-decyl -methacr'ylate, respectively, are obtained.

Example I1.Prepamtion of 3,5,5-'Irinitr0-34120-]-hc.ryl pentenoate 3.5.5-trinitro-3-aza-l-hexyl pentenoate is prepared by the methodof the above example by reacting 3.5.5-trinitro- 3-aza-l-hexanot with redistilled pentcnoic acid containing be varied over a widerange. Pr'eferably,-' however,' the ethylenically unsaturated carbo xy-lic acid is used in stoi-' chiornetric'excess since this has been found to accelerate the rate of formation of the desired ester. m The reaction may be carried out under'any pressure. Under normal circumstances it is most expedient to carry out the reaction at atmospheric pressure. The reaction may be run in the presence .or' in the absence of inert solvents. For example the reaction may be carried ,out in thepresence or water, if desired.

It is sometimes desirable that the reaction mixture be agitated, such as by a mechanical stirrer, so as'to aid in the. tormation oftheester by improving the contact between the reactants. The esters-of this invention I a small amount of'hydroquinone.

The ester is obtained in good yield.

One mole of a-ethyl acrylic acid is reacted with one-half mole of 4,7}7-trinitro-4-aza-octanol in the presence of tritiuoroacetic anhydride. The reaction is carried out for about one hour at 35-50 C. to give 4,7,7-trinitro-4- aza-octyl a-ethyl acrylate.

The novel esters of this invention are inherently useful as explosives due to the presence of a plurality of high energy nitrogroups in the molecule. These esters may also be homopolymerizcd or copolymcrized to form high molecular weight polymers useful-as binders in solid rocket propellants. Binders possessing superior physical properties are obtained by copolymerizingthe esters of this invention with a comonomer containing a plurality of ethylenically unsaturated groups. Typical of'suc'ha comonomer is ethylene glycoldiacrylate- Q It will'bc understood that various modifications'maj" he made inthis invention without departing from the spirit thereof or the scope of the appended claims. 7 -l ClZtlm L 1. As a composition of mattcncompoun hdving the wherein R is selected from the group consisting of hydrogen and lower alkyl, R is selected from the group consisting 'oftlower alkyl and lower nitroalkyl. X, Y'ancl Z 1 arelower alkylene radicals, and m is selected from the groupeonsistingof 0 and l.

d. 2 3. The compoundsof claim 1 wherein :R is methyl;

References. Cited by the: Ex'nminer UNITED STATES PATENTS 1/1961 Gold 260'-486 4/1961 Klager L 260-434 X 4/ 196l 4/1961 r LORRAINE A. WEINBERGER, Primariv Exr zmincr. d LEON ZITVER; Examiner.

D. P; CLARKE; A. .P. HALLUIN, Assistant Examiners.

.1 The compounds of claim 1 wherein R is hydrogen The compound 3,5,5-trini'tro-3'ttzagl-hexyl ncrylatei Vanneman 260 -534 X 7 i v 4 Frankel 'et al. 260-534 X 7 

1. AS A COMPOSITION OF MATTER, COMPOUNDS HAVING THE FORMULA: 